SaaS on Nuxt 4, Postgres (Neon) and Supabase Auth
Multi-tenant SaaS: organizations, role-based memberships, plans/subscriptions, and credit metering.
83 files, 4 tables and 321 lines of schema, verified 2026-08-23 on Nuxt 4, Postgres (Neon) and Supabase Auth.
16 pinned upstream versions
request path. session validation runs in server components and route handlers, not at the edge
What you're getting
Nuxt 4 (framework mode): full-stack Vue SSR: client under app/ (Vite), server under server/ (Nitro), API as server/api/*.post.ts Nitro route handlers.
Postgres on Neon via Drizzle ORM and the postgres-js driver.
Supabase Auth: hosted identity (GoTrue) via the @supabase/ssr cookie client; email+password + OAuth.
Multi-tenant SaaS: organizations, role-based memberships, plans/subscriptions, and credit metering.
Setup
bun add nuxt vue drizzle-orm postgres @supabase/ssr @supabase/supabase-jsDATABASE_URLNeon pooled (-pooler) connection stringNEXT_PUBLIC_SUPABASE_URLNext: your Supabase project URL (RR: VITE_SUPABASE_URL · Nuxt: NUXT_PUBLIC_SUPABASE_URL)NEXT_PUBLIC_SUPABASE_ANON_KEYNext: the project's anon/public key (RR: VITE_SUPABASE_ANON_KEY · Nuxt: NUXT_PUBLIC_SUPABASE_ANON_KEY)SUPABASE_URLReact Router server-side (loaders): same project URL, read off process.env — never inlined into the client bundleSUPABASE_ANON_KEYReact Router server-side: same anon keyApply the schema with bunx drizzle-kit push
Initialization
Database client
Multi-tenant SaaS schema: organizations, billing & usage metering
8 tables, 53 columns and 23 indexes and constraints, applied to a live Postgres (Neon) and asserted to materialize.
organizations4 columns · 3 indexedmemberships5 columns · 3 indexedinvitations10 columns · 4 indexedaudit_log7 columns · 2 indexedapi_keys9 columns · 3 indexedplans5 columns · 2 indexedsubscriptions8 columns · 4 indexedapi_usage5 columns · 2 indexedWhat this schema is built to answer
memberships is indexed by idx_membership_user on user_id, but the RLS policies key on organization_id alone, so the org switcher goes through organizations_for_user(text) — a SECURITY DEFINER function pinned with SET search_path = public and granted to the application role only.
api_usage is append-only and read over idx_usage_org_time (organization_id, created_at): a range scan summing credits_used against the monthly_credits on the plan reached through the organization's single subscriptions row.
The accept path hashes the token it was handed and looks it up under invitations_token_hash_unique — one row, carrying status, role and expires_at. invitations_org_email_unique means a re-invite updates that row instead of leaving a second live token behind.
subscriptions.provider_sub_id is UNIQUE, which is the idempotency key a redelivered event collides on, and provider_event_at rejects an out-of-order one; subscriptions_org_unique keeps exactly one live row per organization for the metering layer to read.
rate_limits is keyed on bucket as its primary key ('signup:203.0.113.4'), sits outside RLS on purpose, and is checked with a single upsert whose CASE both resets an expired window and increments a live one — no select-then-update race.
Organizations & multi-tenancythe tenant boundary every billable and metered row hangs off
Memberships & role-based accessorg↔user join carrying owner/admin/member roles, unique per pair, plus the token-based invitations that create them
Plans & subscription billing tablesthe billable plan catalog and each org's current subscription state
API usage & credit/token meteringhashed API keys plus append-only usage rows that drive quota checks and usage billing
Verified billing (Polar)
Verified tenant isolation
Deploy targets
The app UI
Decisions and compatibility
Client/server split: the DB client, Drizzle schema, records, and webhooks are server-side (server/). The `@/` alias is the client root (app/); server code reaches shared modules via Nuxt's `~~` rootDir alias (e.g. `~~/server/db/schema`).
The API layer is Nitro, Nuxt's server engine: endpoints are server/api/*.post.ts route handlers, and auth mounts as a Nitro catch-all that delegates to the auth library's framework-agnostic web handler.
Nuxt auto-imports components and composables at runtime, but the emitted server code imports h3 helpers (defineEventHandler, toWebRequest) EXPLICITLY — the one deliberate idiom trade so the handlers type-check under standalone tsc instead of relying on the auto-import magic.
Session gating runs in a Nitro server middleware (server/middleware/), which fires on every SSR and API request — the true security boundary, and a real server-side session check rather than a cookie-existence peek.
prepare: false is mandatory — Neon's pooled endpoint is PgBouncer in transaction mode, where server-side prepared statements break across the pool.
Drizzle is paired here (not Prisma): Prisma's prepared-statement reliance is incompatible with transaction-mode pooling.
Hosted: Supabase owns identity in its managed auth.users. This stack emits a LOCAL `user` mirror (db/auth-schema.ts) so app-type schemas can foreign-key `user` directly — keep it in sync with a Supabase trigger on auth.users (insert/update → public.user). The drizzle migration only owns the mirror table's shape, not the trigger.
Sessions are cookie-based (@supabase/ssr): the proxy refreshes them on every request; Server Components read the user via supabase.auth.getUser().
One active subscription per organization (unique on organization_id) — the metering layer reads exactly one.
Usage is an append-only meter (api_usage): roll up by organization + time window for quota and billing rather than mutating a running total.
Rate limits, the super-admin log and the waitlist are deliberately NOT org-scoped: the callers most worth limiting have no organization yet, super-admin actions must outlive the organizations they concern, and a waitlist exists before anyone signs up.
organizations_for_user() is a SECURITY DEFINER function — the only way to answer "which organizations does this user belong to" under policies keyed solely on organization_id. It is granted to the application role alone and must be called with a user id taken from the session, never from a request.
API keys store a SHA-256 of the key and a non-secret prefix — the key itself is shown once, at creation, and cannot be recovered. Revoking sets revoked_at rather than deleting, so a revoked key's usage rows still resolve.
The audit log is append-only at the DATABASE level: RLS scopes it per organization, and the application role has UPDATE and DELETE revoked on it, so the app cannot rewrite its own history.
Invitations store a SHA-256 of the invite token, never the token itself — a database dump cannot be replayed into org access. One row per (organization, email), so re-inviting updates the pending row instead of accumulating dead ones.
How this stack fits together
On Nuxt 4 this stack puts its Postgres (Neon) client at server/lib/db.ts and the Supabase Auth instance at app/middleware/auth.ts and session checks in server/middleware/supabase.ts. Those are the paths this framework's adapter actually emits, not a shared convention: the same SaaS schema and the same Supabase Auth wiring land somewhere different on each of the other frameworks in the registry.
Supabase Auth owns its identity tables in the same database as organizations, memberships, invitations, audit_log, api_keys, plans, subscriptions and api_usage, so the foreign keys reference the local user row directly and a delete cascades through them. No mirror, no webhook, and no window where the two stores disagree.
Postgres (Neon) stores those surrogate keys as uuid, so every foreign key across the 8 tables and 53 columns below is a uuid column. The migration was applied to a live Postgres (Neon) and the tables asserted, not just type-checked.
SaaS
organizations is the boundary, and nearly everything else is downstream of it. memberships joins an organization to a Better Auth user with a role — owner, admin or member, text plus memberships_role_check — under a composite unique on (organization_id, user_id), so the pair is the membership's identity and a duplicate seat is a constraint violation rather than a second row. invitations is how somebody with no account yet arrives: it stores a SHA-256 under invitations_token_hash_unique and never the token, so a database dump is not a pile of working invite links, and one row per (organization, email) makes 'resend' and 'invite again' the same statement. Billing hangs off the same key.
plans is a shared catalog — slug, price_cents, monthly_credits — left outside the tenant boundary on purpose, because every organization reads the same rows. subscriptions holds one row per organization (subscriptions_org_unique) mirroring the provider's state, with provider_sub_id UNIQUE as the webhook idempotency key and provider_event_at as a staleness guard; the billing fragment maps events onto those two columns instead of declaring a table of its own. api_usage is the meter: append-only rows of credits_used rolled up over idx_usage_org_time, never a decremented balance, so a lost write costs you an entry rather than a wrong total. On Postgres the isolation is not advisory.
Each org-scoped table gets ENABLE plus FORCE ROW LEVEL SECURITY and a policy comparing its organization_id against current_setting('app.current_org_id'), reached through a dedicated NOBYPASSRLS role — Neon's default owner carries BYPASSRLS and would make the whole arrangement silently inert. Unset context reads as NULL, which matches nothing, so the failure mode is no rows rather than every row. audit_log is scoped the same way and additionally has UPDATE and DELETE revoked from the application role, which is the difference between a log and evidence. MySQL has no RLS, so that dialect ships forOrg() instead: fail-closed, app-enforced, and disclosed as the weaker guarantee. Three tables sit outside all of it deliberately.
rate_limits is keyed on an opaque bucket string because the callers worth throttling have no organization yet, waitlist predates signup entirely, and admin_audit stores an organization_id carrying no foreign key, so the entry recording a deletion outlives what it deleted.
Nuxt 4
Nuxt 4 in framework mode is the one stack here with two roots. Client code lives under app/ and is what `@/` points at (Vite, Vue single-file components); server code lives under server/ and is run by Nitro, Nuxt's server engine. The database layer is server-side, so initCode writes server/lib/db.ts and the schema, record modules and webhooks land under server/db/ and server/api/ — server modules reach each other through Nuxt's `~~` rootDir alias (`~~/server/lib/db`, `~~/server/db/schema`), never through `@/`. That split earns its keep with secrets: the Resend send client belongs to ~~/server/lib/email, and nothing under app/ can import it by accident. The API layer is Nitro rather than a React-shaped route file.
server/api/webhooks/polar.post.ts is a POST endpoint; auth mounts as the catch-all server/api/auth/[...all].ts, which adapts the H3 event with toWebRequest(event) and hands the resulting web Request to the auth library's framework-agnostic handler. Nuxt auto-imports defineEventHandler and its siblings at runtime, but the emitted server files import them from h3 explicitly — one deliberate idiom trade so every handler type-checks under standalone tsc. Session gating is a Nitro server middleware at server/middleware/auth.ts. It fires on every SSR render and every API request, filters on pathname prefixes (/dashboard, /settings), performs the real auth.api.getSession() lookup, and answers with sendRedirect(event, "/sign-in", 302). Because Nitro sits in front of both the rendered page and the endpoints, that is a genuine security boundary rather than a cheap pre-render bounce.
On the client, Vue does its own thing: the auth binding exposes signIn/signUp/useSession as Vue refs, screens are .vue components under app/pages/ (sign-in.vue, dashboard/[id].vue), chrome lives in app/components/ and app/layouts/, and SPA-side guards are app/middleware/*.ts. The design system is shadcn-vue on reka-ui — a real re-port, not the React components wearing new names — and it is checked with vue-tsc, since plain tsc cannot parse an SFC.
Postgres (Neon)
Postgres here is Neon reached through postgres-js, with Drizzle's pg-core dialect on top: drizzle({ client }) over a single module-level postgres(DATABASE_URL, { prepare: false }). That flag is not a preference. Neon's pooled (-pooler) endpoint is PgBouncer in transaction mode, where a backend is handed to a different session between statements, so server-side prepared statements break across the pool — and the same constraint is why this axis pairs with Drizzle rather than Prisma. One client per module is enough: PgBouncer and the runtime do the pooling, so there is no globalThis singleton dance. The schemas built on this dialect make three recurring type decisions. Primary keys are uuid(...).primaryKey().defaultRandom(), so ids come from the database. Timestamps are timestamp(..., { withTimezone: true }).defaultNow() — timestamptz, an absolute instant.
Closed value sets are text plus a CHECK constraint rather than pgEnum, so shipping a new role or subscription status is an ordinary constraint change instead of an ALTER TYPE migration. Counters are bigint({ mode: "number" }), and Better Auth's text user.id is referenced as text by the app tables rather than recast. Operationally, transaction-mode pooling forbids anything that spans statements on one backend: LISTEN/NOTIFY, session-scoped SET, advisory-lock sessions, WITH HOLD cursors. Those paths use Neon's direct endpoint instead. The connection client also changes with the deploy target — max: 1 per short-lived serverless instance, a real reused pool (max 10, idle_timeout 20) in a long-running Node process, and on Cloudflare Workers postgres-js is replaced outright by @neondatabase/serverless over HTTP, because Workers have no TCP sockets.
The capability that exists only on this side of the matrix is row-level security. Multi-tenant schemas ship ENABLE plus FORCE ROW LEVEL SECURITY with policies keyed on current_setting('app.current_org_id', true), which withTenant() sets per transaction — unset context yields no rows, so isolation fails closed inside the database rather than in application code. It requires a dedicated NOBYPASSRLS role: Neon's default neondb_owner carries BYPASSRLS, and connecting as it makes every policy silently inert.
Supabase Auth
Supabase Auth is a hosted service — GoTrue — that your app reaches over cookies rather than an SDK session object. Credentials and the canonical user records live in Supabase's managed auth.users schema. What lands in your own database is a mirror: db/auth-schema.ts declares user keyed by the Supabase auth uid (text; varchar(255) on MySQL) with email, full name, avatar URL and timestamps, so app-type schemas can foreign-key user exactly as they would under a self-hosted auth. Unlike the Clerk fragment, no sync webhook is emitted here, because Supabase's own trigger mechanism is the intended path: a trigger on auth.users writing into public.user lives in the Supabase project, not in the drizzle migration.
The migration owns the mirror's column shape and nothing else, so wiring that trigger is a step you take before those foreign keys mean anything. The mechanic that actually shapes this adapter is cookie refresh. @supabase/ssr rotates the auth token, and a rotated cookie only reaches the browser if something writes it onto the outgoing response — which is why every framework branch is built around the same getAll/setAll pair, wired to whatever that framework calls a cookie jar. Next's src/proxy.ts rebuilds the NextResponse inside setAll before calling getUser().
React Router has no middleware layer, so app/lib/supabase/server.ts constructs the client per request and returns { supabase, headers }, and the protected layout route attaches those headers to both exits — the redirect and the pass-through — so a refresh that happened during a guard is not lost. Nuxt's server/utils/supabase.ts binds the client to the h3 event and writes through setCookie, with a Nitro middleware doing the guard. Every decision point calls supabase.auth.getUser(), never getSession(): getSession reads whatever the cookie claims, getUser revalidates it against Supabase. Because a browser client is emitted alongside the server one, the auth screens are real forms calling supabase.auth.signInWithPassword rather than a hosted widget, and the sidebar's user menu subscribes to onAuthStateChange. Two consequences to plan around.
The anon key is public by design and is inlined into the client bundle under whichever prefix the framework demands (NEXT_PUBLIC_, VITE_, NUXT_PUBLIC_), so protection has to come from row-level security on Supabase's side, not from keeping the key quiet. And every guard is a network call to Supabase, not a local query — cheap, but not free, and on the path of every protected request.
